Flap seal

ABSTRACT

The invention relates to a flap seal in the form of a lamella seal, comprising at least three essentially flat individual rings ( 1, 10 ) lying one on top of another in a bundle-type form. Said individual rings ( 1, 10 ) comprise an inner part which is respectively defined by an inner circumferential surface ( 2, 11 ). The outer-lying individual rings ( 1 ) are covering rings, and the inner-lying individual rings ( 10 ) are sealing rings. High-quality sealing surfaces can be produced by allocating positioning means to the covering rings ( 1 ) for positioning said covering rings ( 1 ) in relation to one another in the circumferential direction and/or in relation to inner-lying sealing rings ( 10 ) in the radial direction. The positioning means also enable a relative movement in the axial direction.

BACKGROUND OF THE INVENTION

The present invention relates to a flap seal of the type for a lamellaseal.

Flap seals of this type are known in the practice and are deployed, forexample, with throttle valves in steam conduits.

A seal of this type is disclosed, for example, in DE 298 22 791 U1. Theflap seal shown therein includes two cover rings which surround a packetof sealing rings. This flap seal is formed by initially assemblingtogether annular discs in a packet-type manner. The metallic ringsinclude on the inner sides thereof inwardly oriented noses which, uponmounting of the disc packets, together under axial pressure, are weldedto one another and the flap seal is thus permanently secured together.After this welding, the flap seal is brought by cutting or shaving intoits designated form, which corresponds to the sleeve surface of aconical section of an inclined or tapered cone.

Otherwise, it is known in connection with conventional flap seals toassemble these together as well prior to the cutting or shaving work,with the individual lamellae being adhered to one another.

It is problematic in connection with these flap seals that they can nolonger be divided or separated from one another after the cutting orshaving work. For this reason, the cover discs, which are typicallyformed of metal, and the sealing discs disposed therebetween, cannot bede-burred separately from one another. The de-burring of the fixedpackets of discs comprised of materials which typically differ from oneanother therefore does not lead to an optimal surface quality of theseal surface.

It is, therefore, the object of the present invention to create a flapseal the individual discs of which can be collectively worked or handledwhile the individual discs are securely mounted to one another, theindividual discs of which can, further, be separated from one anotherfor de-burring work thereon as desired and, following the de-burring,can be assembled together again in substantially the originalorientation.

SUMMARY OF THE INVENTION

Due to the arrangement of positioning means relative to the cover rings,which position the cover rings relative to one another in thecircumferential direction and/or relative to the inwardly disposed sealrings in a radial direction and which permit relative movement of thecover rings in the axial direction, the rings can be assembled togetherin the designated orientation, axially pressed, and then worked on inthe assembled condition. They can then be again separated in the axialdirection. The rings can then be de-burred and again assembled togetherin the original orientation. The pressing of the flap seal in the valveduring the mounting step occurs, as well, in the axial direction.

Advantageous embodiments of the invention are set forth in the dependentclaims. In view of the fact that, in connection with the inventivemethod, there initially occurs a stacking of the individual rings in thedesignated serial arrangement, whereby the individual rings arereleasably fixedly secured to one another radially and in thecircumferential direction, then the finishing of the outer contour viacutting or shaving work, the thereafter-following separation of theindividual rings, the de-burring of the individual rings, to the extentrequired, and, eventually, the assembling together of the individualrings in the original orientation and serial arrangement, as well as amounting of the individual rings under axial pressure, a flap seal isproduced whose individual rings have been finished or worked in apredetermined manner. The mounting then follows again in the arrangementby which the designated contour is ensured. The configuration of theworked surfaces of the individual rings is substantially improved incomparison to that effected by the known processes.

BRIEF DESCRIPTION OF THE DRAWINGS

There follows hereinafter a description of an embodiment of the presentinvention with reference to the figures of the drawing.

The figures of the drawings show:

FIG. 1: A cover ring of an inventive flap seal shown in an axial planview thereof;

FIG. 2: The cover ring shown in FIG. 1 in a sectional side view thereof;

FIG. 3: A seal ring shown in a top plan view, as well as

FIG. 4: An inventive flap seal shown in a side sectional view.

DESCRIPTION OF PREFERRED EMBODIMENTS

As seen in FIG. 1, a cover ring 1 of an inventive flap seal is shown inan axial plan view. The cover ring 1, as is the case with other typicalindividual rings of a flap seal, is substantially annularly shapedbefore it is subjected to working. Individual clips 3 are provided aspositioning means on an inner circumferential surface 2 of the coverring 1,. The clips 3 are, in this connection, comprised of fourpositioning means, each disposed at respective positions around thecircumferential direction 90 degrees offset from one another. In thisconnection, two of the offset positions, which are offset to one anotherby 180 degrees, are provided with a clip in the form of a nose-shapedpositioning means 5, while the other two offset positions, which liebetween the nose-shaped positioning means 5, have respective clipsdisposed thereat in the form of fork-shaped positioning means 6. Theindividual clips 3 of the fork-shaped positioning means 6 are disposedat a spacing from one another which corresponds to the width of anose-shaped positioning means 5. The clips 3 are bent at an angle ofapproximately 90 degrees relative to the plane of the cover ring 1 inthe axial direction and extend to one side of the plane of the coverring 1.

Continuing, on the inner circumferential surface, an index marker 7 isdisposed between a nose-shaped positioning means 5 and a fork-shapedpositioning means 6.

FIG. 2 shows the cover ring 1 shown in FIG. 1 in a side sectional viewthereof. It can be seen that the clips 3 are formed as individuallyformed material portions bent downwardly from the plane of the coverring 1.

FIG. 3 shows a seal ring 10 in a plan view thereof along the axialdirection, corresponding to the illustration shown in FIG. 1. The sealring 10 is, as well, annularly shaped before the working thereof andcomprises an inner circumferential surface 11, having a respectivecutout 12 formed at each respective one of four positions disposed at 90degree offsets from another. The cutouts 12 are dimensioned to the fullaxial height of the inner circumferential surface 11 and extend in thecircumferential direction to a respective width which corresponds to theouter dimension of a fork-shaped positioning means 6.

FIG. 4, consequently, shows a finished or completely worked flap discseal with an upper cover ring 1 and a lower cover ring 1, as well as aseal ring 10 disposed therebetween. The outer circumferential surface ofthe flap seal is configured via cutting or shaving work incorrespondence with the configuration of a conical section of aninclined or tapered circular cone.

The preparation of the flap seal as shown in FIG. 4 comprising thecomponents shown in FIGS. 1-3, is effected in the following manner:

Initially, two identical cover rings 1 are prepared from suitable sheetmetal, such as, for example, via laser cutting. The clips 3 are bent outto one side of the plane of the cover ring 1. The seal ring 10 is formedout of a suitable material in a similar manner. The material can, inthis connection, be a halogenated plastic, graphite, or can be, as well,metal. A plurality of seal rings 10 can also be deployed.

Now the seal ring 10 is engaged on both sides by respective cover rings1 and, indeed, in a manner such that the markings 7 of the two coverrings 1 coincide with one another in the axial direction. The clips 3 ofthe cover rings 1 face one another. Via this orientation, thenose-shaped positioning means 5 are received in the in-between spaces ofthe fork-shaped means 6. The fork-shaped positioning means 6 aredisposed in the cutouts 12 of the seal ring 10. In this manner, bothcover rings 1, as well as the seal ring 10, are secured against turningmovement and displacement movement in the plane of the ring. Thearrangement remains, however, axially compressible.

The packet is now pressed in a suitable apparatus and subjected toworking such that the conventional outer contour, as shown in FIG. 4, isproduced. Now, the individual rings can be again taken apart from oneanother and the worked outer side can be de-burred, such that a desiredtop surface quality is achieved. due to the unique fixed securement ofthe flap seal via the positioning means 5, 6 and the cutouts 12, there-assembly together of the cover rings 1 and the seal ring 10 leads tothe flap seal being assembled together in the same orientation as it hadas it was subjected to working. Thereafter, the assembled packet can bemounted in a conventional mounting of a flap seal valve via axialpressing.

The assembly comprises in its entirety a flap seal which provides asubstantially improved top surface quality with relatively simpleworking.

In contrast to the heretofore known flap seals, the inventive flap sealprovides the further advantage that the individual rings no longer needbe adhered to one another or welded to one another. This work step canbe omitted. In contrast to flap seals formed by adhesion, the furtheradvantage is obtained with the inventive flap seal that, for the firsttime, PTFE-comprising seal rings, which cannot be adhered to oneanother, can be used. It is additionally possible to finish the outercontours of the cover rings slightly smaller than the seal ring. In thismanner, it can be avoided that the valve seat comes into contact withthe cover rings and eventually prematurely wears away the cover rings.

These significant advantages are provided not only in connection withthe illustrated arrangement of two cover rings 1 and a seal ring 10.Rather, seal rings comprising alternating graphite and metal rings or alarge number of graphite rings can also be deployed. It is also possibleto deploy a plurality of seal rings 10, which are collectively formed ofmetal. The separate follow-on work possibilities permit, as well, a highlevel of quality of the subsequently formed seal surfaces.

In addition to the afore-described embodiments, the seal ring can alsocomprise an inner circumferential surface which deviates from theafore-described sleeve surface of an annular cylinder. Thus, forexample, the inner cutout delimited by the seal ring can have multipleangles and, especially, can have a quadratic shape.

The specification incorporates by reference the disclosure of Germanpriority document 100 30 300.5 filed Jun. 27, 2000 and PCT/EP01/02770filed Mar. 13, 2001.

The present invention is, of course, in no way restricted to thespecification disclosure of the specification and drawings, but alsoencompasses any modification within the scope of the appended claims.

What is claimed is:
 1. A flap seal comprising: at least one seal ringhaving an inner cutout forming an inner surface; and at least two coverrings each having an inner cutout forming an inner surface, the coverrings and the seal ring being stacked one upon the other such that theseal ring is intermediate the cover rings relative to a stacking axis,and the cover rings including positioning means operable to maintain atleast one of the cover rings at fixed relative circumferential positionsto one another and the cover rings at fixed radial positions relative tothe seal ring while permitting relative movement of the rings in theaxial direction.
 2. A flap seal according to claim 1, wherein thepositioning means of the cover rings include clips arranged in theregion of the inner circumferential surfaces, the clips extendingoutwardly from the plane of the cover rings.
 3. A flap seal according toclaim 2, wherein each clip includes a receiving component having a pressfit gap and an insertion component receivable in the press fit gap ofthe receiving component with respective ones of the receiving componentsextending from one of the cover rings and respective ones of theinsertion components extending from the other cover ring such that eachrespective insertion component on a cover ring is received in a pressfit manner in a respective receiving component to thereby effectreleasable securement of the cover rings to one another.
 4. A flap sealaccording to claim 2, wherein the receiving and insertion components ofthe clips are arranged in alternating manner in the circumferentialdirection of the inner circumferential surface of the cover rings.
 5. Aflap seal according to claim 1, wherein both cover rings are identicallyconfigured and are arranged with their positioning means facing oneanother, with the positioning means being in the form of clips, eachclip including a receiving component having a press fit gap and aninsertion component receivable in the press fit gap of the receivingcomponent with respective ones of the receiving components extendingfrom one of the cover rings and respective ones of the insertioncomponents extending from the other cover ring such that each respectiveinsertion component on a cover ring is received in a press fit manner ina respective receiving component to thereby effect releasable securementof the cover rings to one another.
 6. A flap seal according to claim 1,wherein the positioning means is disposed on the inner circumferentialsurface of the seal ring so that the seal ring is secured relative tothe cover rings in the radial direction.
 7. A flap seal according toclaim 1, wherein both cover rings are in contact via their positioningmeans at at least three locations with the inner circumferential surfaceof the seal ring.
 8. A flap seal according to claim 1, wherein the innercircumferential surface of the inner seal ring comprises cutouts inwhich the positioning means are received and which fix the seal ring inthe circumferential direction relative to both cover rings.
 9. A flapseal according to claim 1, wherein the seal ring is formed of a plasticmaterial, especially a PTFE-comprising plastic, or graphite.
 10. Amethod for producing a packet-type flap seal having individual rings,the method comprising: stacking at least one seal ring having an innercutout forming an inner surface and at least two cover rings each havingan inner cutout forming an inner surface in a designated serialarrangement, the cover rings and the seal ring being stacked one uponthe other such that the seal ring is intermediate the cover ringsrelative to a stacking axis, and positioning means of the cover ringsoperate to maintain at least one of the cover rings at fixed relativecircumferential positions to one another and the cover rings at fixedradial positions relative to the seal ring while permitting relativemovement of the rings in the axial direction; finishing the outercontour of the flap ring via cutting or shaving work; separating theindividual rings; de-burring the individual rings, to the extentrequired; and assembling together the individual rings in the originalorientation and serial arrangement to thereby dispose the flap seal incondition for subsequent mounting thereof under axial pressure in asealing location.